[Poultry resistance to typhoid-pullorum disease by sex and breed]

Studied was the resistance of a total of 1729 birds of the Leghorn, Cornish, and White Plymouth Rock breeds with regard to typhoid and pullorum disease after the oral infection with strain 2348 of Salmonella pullorum and strain 2307 of Salmonella gallinarum. In accordance with the manifested clinical picture and the results of the bacteriologic investigations all birds were divided into three groups--unaffected, survived, and died. There existed breed- and sex-associated variations in the resistance, resp., the susceptibility of birds to both strains of Salmonellae. Highest was the resistance of the Leghorn birds, followed by those of the Cornish breed. Most susceptible proved the birds of the White Plymouth Rock breed. The cocks seemed to be more resistant than the hens. Besides, there was a trend in the females in transferring resistance to both strains, which was common in al birds.